Oil is generally used as a lubricant to reduce friction between moving parts in a mechanical system, such as an engine or a transmission in a locomotive, for example. The oil is free of contaminants when it is first put into the engine, but over time collects wear and corrosion products which contaminate the oil. For example, metal particulates are produced by abrasion or chemical corrosion in the engine during normal operation, and even more so during high duty cycle operations such as those associated with operation of a locomotive engine. Oil filters in the engine remove larger particles from the oil, but smaller contaminants are not removed by the filter, and instead accumulate in the oil over time.
In many industries, and particularly in the railroad transportation industry, it is important to detect impending mechanical failure before the failure occurs or a condition causing the impending failure worsens. To this end, chemical and/or physical analysis of periodic oil samples taken from a locomotive engine can provide an indication of wear status of the locomotive engine and other associated components, such as drive or hydraulic systems. Specifically, analysis of a concentration of the metal particulates in oil over time provides an indication of engine stress or engine wear and, more particularly, analysis of trends in the concentration of metal particulates provides an indication of impending mechanical failure or deteriorating engine conditions. In addition, other types of analyses of the oil, such as testing for the presence of water or other contaminants, as well as trend analysis of concentrations of these other contaminants, provides additional indication of the condition of the engine and any impending mechanical failures thereof. For example, detection of water in the oil may be indicative of a leak in the engine, such as from a deteriorating gasket, for example, while a decreasing flashpoint of the oil may indicate a fuel-to-oil leak.
Typical techniques used to analyze oil include particle size analysis, magnetic chip detection methods, ultrasonic reflectometry, ferrography, x-ray fluorescence and emission spectroscopy, for example. Spectrographic analysis, for example, is a popular method of oil analysis which provides concentrations, typically in parts-per-million (PPM), of metallic substances in the oil. The concentrations are monitored over time, and once a critical concentration (based on a predetermined set point) is reached, maintenance is performed on the engine to prevent any impending failure from occurring.
However, a typical diesel engine used in a locomotive uses a considerable amount of oil during the life cycle of the engine, due to high duty cycle operations associated with railroad transportation. As a result, the oil in a locomotive engine is changed or added to frequently. Changing or adding to the oil in the engine affects concentrations of the contaminants in the oil, and actual trends in these concentrations is thereby lost. This results in a decrease in accuracy of predicting impending engine failures, thereby causing an increase in catastrophic failures and/or resultant corrective maintenance requirements for the engines, also resulting in increased repair costs and down time of the engines.
In addition, manual tracking of trends in concentrations of contaminants in oil is overly cumbersome, particularly for a typical major freight railroad corporation, since these corporations utilize hundreds of locomotives for transportation of freight or passengers. As a result, it is impossible to provide timely feedback of manually-tracked trends in the concentrations of the contaminants in the oil in order to effectively prevent failures in the engines of the locomotives.
Accordingly, it is desired to develop an oil sample analysis calculator which overcomes the problems described above. More specifically, it is desired to develop an oil sample analysis calculator which accurately and efficiently predicts trends in concentrations of oil contaminants when oil is changed and/or added throughout the lifecycle of an engine.